Projection lens system
US8570661B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 30, 2011 |
| Grant date | Oct 29, 2013 |
| Priority date | — |
| Expiry date | Jan 2, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/18
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection lens system includes, in order from a screen-side to an SLM-side thereof, a first lens group of negative refractive power which includes a first lens, and a second lens group of positive refractive power. The second lens group includes a second to fifth lenses in order from the screen-side to the SLM-side of the projection lens system. The projection lens system satisfies the following condition formulas: 1.95<|F1/Fw|<2.15, 0.5<|f4/Fw|<0.7, and 1.05<|f5/Fw|<1.25, where F1 is the effective focal length of the first lens group, f4 is the focal length of the fourth lens, and f5 is the focal length of the fifth lens, Fw is the effective focal length of the projection lens system which is in the wide-angle state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.